Molecular Plant Breeding 2025, Vol.16, No.1, 82-92 http://genbreedpublisher.com/index.php/mpb 89 phenotyping, and screening techniques to enhance heat tolerance. This comprehensive approach has expanded the understanding of factors influencing yield under stress and identified promising strategies for breeding. Additionally, Ni et al., (2017) reviewed recent progress in understanding the molecular mechanisms of heat tolerance, including phytohormone signaling and epigenetic regulation. These insights have informed integrative strategies to improve heat tolerance by utilizing existing germplasm, modern cultivars, landraces, and related species. Furthermore, Driedonks et al., (2016) highlighted the need for a multidisciplinary approach involving governmental agencies, private companies, and academic institutions to address the complex nature of plant heat tolerance. These implementation experiences demonstrate the effectiveness of collaborative and integrative strategies in breeding heat-tolerant wheat varieties, ensuring their success in mitigating the impacts of global warming on wheat production. 8 Challenges and Future Directions in Wheat Heat Tolerance Breeding 8.1 Phenotypic complexity and environmental adaptability The diversity and complexity of heat tolerance traits in wheat under high temperatures present significant challenges for breeders. Heat tolerance in wheat is influenced by a multitude of phenological, physiological, and biochemical traits, which exhibit substantial genotypic and environmental variations. For instance, traits such as grain yield, grain-filling duration, spike length, and canopy temperature have been identified as critical indicators of heat tolerance, but their expression can vary widely depending on environmental conditions (Al-ashkar et al., 2023; Kumar et al., 2023). Additionally, the interaction between genotype and environment (G x E) complicates the selection process, as traits that confer heat tolerance in one environment may not be as effective in another (Reynolds et al., 2004). This phenotypic complexity necessitates the use of multidimensional analyses and comprehensive indices to accurately classify and select heat-tolerant genotypes (Al-ashkar et al., 2023). 8.2 Data integration and multidisciplinary collaboration The integration of omics data (genomics, transcriptomics, proteomics, and metabolomics) with phenotypic and environmental data is crucial for advancing heat tolerance breeding in wheat. Multidisciplinary collaboration is essential to harness the full potential of these diverse data sources. For example, genome-wide association studies (GWAS) have identified numerous QTLs associated with heat tolerance, which can be used for marker-assisted selection (Paliwal et al., 2012; Khan et al., 2022a). However, the successful application of these findings requires collaboration between geneticists, physiologists, and breeders to ensure that the identified markers are effectively integrated into breeding programs. Additionally, the development of advanced phenotyping techniques and the use of high-throughput screening methods can enhance the accuracy and efficiency of selecting heat-tolerant genotypes (Yang et al., 2002; Langridge and Reynolds, 2021). 8.3 Heat tolerance breeding strategies in the context of climate change As global temperatures continue to rise, breeding strategies must adapt to ensure that wheat varieties can cope with future climate conditions. One approach is to focus on the genetic improvement of key physiological traits that confer heat tolerance, such as canopy temperature depression, membrane thermostability, and photosynthetic efficiency (Reynolds et al., 2004; Kamara et al., 2021). Another strategy involves the use of genetic resources from heat-tolerant wheat species, such as emmer wheat, to introduce valuable alleles into modern bread wheat cultivars (Ullah et al., 2021). Additionally, breeding programs should prioritize the development of genotypes with stable yield performance across a range of stress scenarios, including combined drought and heat stress, which are likely to become more prevalent with climate change (Tricker et al., 2018). By adopting these adaptive strategies, breeders can enhance the resilience of wheat to high temperatures and ensure food security in the face of a changing climate. Acknowledgments Thanks to the anonymous peer reviewers for providing constructive suggestions for revisions of this manuscript.
RkJQdWJsaXNoZXIy MjQ4ODYzNA==